Terror in the Ashes (Ashes Series #15) by William W. Johnstone
"I usually give the enemy one chance to surrender. After that, I don't take prisoners." Ben Raines
Having reclaimed American soil from the savage armies of terrorists, lawless street gangs, and mutant Night People, Ben Raines and his Rebel army have a new mission: to free the British Isles from a tyranny of evil oppression.
After Rebel forces establish a beachhead at the Irish seaport of Galway, Raines orders a massive armored assault to drive out the mercenary army of the insidious warlord Jack Hunt. The Rebels' search-and-destroy mission crushes enemy resistance. . .but reinforcements for Hunt's crumbling army bring with them the most hideous foe Ben Raines has yet faced. Raines and his Rebels must choose between saving themselves or sacrificing their cause to save the lives of innocent civilians trapped in a beleaguered land.